From 7dfcc480ba1e19bd3232349fc733caef94034292 Mon Sep 17 00:00:00 2001
From: stainer_t <thomas.stainer@oecd-nea.org>
Date: Mon, 8 Sep 2025 13:48:49 +0200
Subject: Initial commit from Polytechnique Montreal

---
 doc/IGE344/SectDTHM.tex | 304 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 304 insertions(+)
 create mode 100644 doc/IGE344/SectDTHM.tex

(limited to 'doc/IGE344/SectDTHM.tex')

diff --git a/doc/IGE344/SectDTHM.tex b/doc/IGE344/SectDTHM.tex
new file mode 100644
index 0000000..c546b00
--- /dev/null
+++ b/doc/IGE344/SectDTHM.tex
@@ -0,0 +1,304 @@
+\subsection{Contents of \dir{thm} data structure}\label{sect:thmdir}
+
+This data structure contains the thermal-hydraulics information required in a multi-physics calculation
+
+\subsubsection{The main \dir{thm} directory}\label{sect:thmdirmain}
+
+The following records and sub-directories will be found in the first level of a \dir{thm} directory:
+
+\begin{DescriptionEnregistrement}{Main records and sub-directories in \dir{thm}}{8.0cm}
+\CharEnr
+  {SIGNATURE\blank{3}}{$*12$}
+  {parameter $\mathsf{SIGNA}$ containing the signature of the data structure}
+\IntEnr
+  {STATE-VECTOR}{$40$}
+  {array $\mathcal{S}^{th}_{i}$ containing various integer parameters that are required to describe this data structure}
+\RealEnr
+  {REAL-PARAM\blank{2}}{$40$}{}
+  {array $\mathcal{R}^{th}_{i}$ containing various floating-point parameters that are required to describe this data structure}
+\RealEnr
+  {MESHZ\blank{7}}{$\mathcal{S}^{th}_{1}$}{m}
+  {initial axial meshes as recovered from the fuelmap}
+\RealEnr
+  {REF-RAD\blank{5}}{$(\mathcal{S}^{th}_{7}-1)\times\mathcal{S}^{th}_{1}$}{m}
+  {initial radial meshes as recovered from the first call to {\tt THM:} module}
+\RealEnr
+  {NB-FUEL\blank{5}}{$\mathcal{S}^{th}_{2}$}{}
+  {number of active fuel rods in a single assembly or number of active fuel pins in the cluster}
+\RealEnr
+  {NB-TUBE\blank{5}}{$\mathcal{S}^{th}_{2}$}{}
+  {number of active guide tubes in a single assembly}
+\RealEnr
+  {FRACT-PU\blank{4}}{$\mathcal{S}^{th}_{2}$}{}
+  {plutonium mass enrichment}
+\OptRealEnr
+  {KCONDF\blank{6}}{$\mathcal{S}^{th}_{16}+3$}{$\mathcal{S}^{th}_{12}\ne 0$}{}
+  {coefficients of the user-defined correlation for the fuel thermal conductivity}
+\OptCharEnr
+  {UCONDF\blank{6}}{$12$}{$\mathcal{S}^{th}_{12}\ne 0$}
+  {string variable set to {\tt KELVIN} or to {\tt CELSIUS}}
+\OptRealEnr
+  {KCONDC\blank{6}}{$\mathcal{S}^{th}_{17}+3$}{$\mathcal{S}^{th}_{13}\ne 0$}{}
+  {coefficients of the user-defined correlation for the clad thermal conductivity}
+\OptCharEnr
+  {UCONDC\blank{6}}{$12$}{$\mathcal{S}^{th}_{13}\ne 0$}
+  {string variable set to {\tt KELVIN} or to {\tt CELSIUS}}
+\RealEnr
+  {ERROR-T-FUEL}{1}{K}
+  {absolute error in fuel temperature}
+\RealEnr
+  {ERROR-D-COOL}{1}{g/cc}
+  {absolute error in coolant density}
+\RealEnr
+  {ERROR-T-COOL}{1}{K}
+  {absolute error in coolant temperature}
+\RealEnr
+  {ERROR-P-COOL}{1}{Pa}
+  {absolute error in coolant pressure}
+\RealEnr
+  {MIN-T-FUEL\blank{2}}{1}{K}
+  {minimum fuel temperature}
+\RealEnr
+  {MIN-D-COOL\blank{2}}{1}{g/cc}
+  {minimum coolant density}
+\RealEnr
+  {MIN-T-COOL\blank{2}}{1}{K}
+  {minimum coolant temperature}
+\RealEnr
+  {MIN-P-COOL\blank{2}}{1}{Pa}
+  {minimum coolant pressure}
+\RealEnr
+  {MAX-T-FUEL\blank{2}}{1}{K}
+  {maximum fuel temperature}
+\RealEnr
+  {MAX-D-COOL\blank{2}}{1}{g/cc}
+  {maximum coolant density}
+\RealEnr
+  {MAX-T-COOL\blank{2}}{1}{K}
+  {maximum coolant temperature}
+\RealEnr
+  {MAX-P-COOL\blank{2}}{1}{Pa}
+  {maximum coolant pressure}
+ \DirEnr
+  {HISTORY-DATA}
+  {sub-directory containing the historical values taken by the thermal-hydraulics parameters (mass flux, density, pressure, enthalpy, temperature)
+  in the coolant and in the fuel rod for the whole geometry}
+\OptRealEnr
+  {RAD-PROF\_R\blank{2}}{$\mathcal{S}^{th}_{18}$}{$\mathcal{S}^{th}_{18}\ne 0$}{m}
+  {abscissas of the user-defined radial form factor table}
+\OptRealEnr
+  {RAD-PROF\_F\blank{2}}{$\mathcal{S}^{th}_{18}$}{$\mathcal{S}^{th}_{18}\ne 0$}{ }
+  {form-factor values of the user-defined radial form factor table}
+\OptRealEnr
+  {TIME-SR1\blank{2}}{$\mathcal{S}^{th}_{19}$}{$\mathcal{S}^{th}_{19}\ne 0$}{s}
+  {tabulation abscissa in time}
+\OptRealEnr
+  {POWER-SR1\blank{2}}{$\mathcal{S}^{th}_{19}$}{$\mathcal{S}^{th}_{19}\ne 0$}{ }
+  {tabulation power factor corresponding to each tabulation abscissa in time}
+\end{DescriptionEnregistrement}
+
+The signature for this data structure is $\mathsf{SIGNA}$=\verb*|L_THM|. The array $\mathcal{S}^{h}_{i}$
+contains the following information: 
+
+\begin{itemize}
+\item $\mathcal{S}^{th}_{1}$ contains the number of axial meshes $N_{\rm z}$.
+\item $\mathcal{S}^{th}_{2}$ contains the number of channels in the radial plane $N_{\rm ch}$.
+\item $\mathcal{S}^{th}_{3}$ contains the maximum number of iterations for computing the
+conduction integral.
+\item $\mathcal{S}^{th}_{4}$ contains the maximum number of iterations for computing the
+center pellet temperature.
+\item $\mathcal{S}^{th}_{5}$ contains the maximum number of iterations for computing the
+coolant parameters (velocity, pressure, enthapy, density) in case of a transient calculation.
+\item $\mathcal{S}^{th}_{6}$ contains the number of discretisation points in fuel.
+\item $\mathcal{S}^{th}_{7}$ contains the number of total discretisation points in the whole fuel rod (fuel+cladding) $N_{\rm dtot}$.
+\item $\mathcal{S}^{th}_{8}$ contains the type of calculation performed by the \moc{THM:} module:
+
+\begin{displaymath} \mathcal{S}^{th}_{8} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{steady-state calculation} \\
+ 1 & \textrm{transient calculation.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{9}$ contains the current time index.
+\item $\mathcal{S}^{th}_{10}$ flag to set the gap correlation:
+
+\begin{displaymath} \mathcal{S}^{th}_{10} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{built-in correlation is used} \\
+ 1 & \textrm{set the heat exchange coefficient of the gap as a user-defined constant.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{11}$ flag to set the heat transfer coefficient between the clad and fluid:
+
+\begin{displaymath} \mathcal{S}^{th}_{11} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{built-in correlation is used} \\
+ 1 & \textrm{set the heat exchange coefficient between the clad and fluid as a user-defined constant.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{12}$ flag to set the fuel thermal conductivity:
+
+\begin{displaymath} \mathcal{S}^{th}_{12} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{built-in correlation is used} \\
+ 1 & \textrm{set the fuel thermal conductivity as a function of a simple user-defined correlation.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{13}$ flag to set the clad thermal conductivity:
+
+\begin{displaymath} \mathcal{S}^{th}_{13} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{built-in correlation is used} \\
+ 1 & \textrm{set the clad thermal conductivity as a function of a simple user-defined correlation.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{14}$ type of approximation used during the fuel conductivity evaluation:
+
+\begin{displaymath} \mathcal{S}^{th}_{14} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{use a rectangle quadrature approximation} \\
+ 1 & \textrm{use an average approximation.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{15}$ type of subcooling model:
+
+\begin{displaymath} \mathcal{S}^{th}_{15} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{use the Bowring correlation} \\
+ 1 & \textrm{use the Saha-Zuber correlation.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{16}$ contains the number of terms in the user-defined correlation for the fuel thermal conductivity (if $\mathcal{S}^{th}_{12}=1$).
+\item $\mathcal{S}^{th}_{17}$ contains the number of terms in the user-defined correlation for the clad thermal conductivity (if $\mathcal{S}^{th}_{13}=1$).
+\item $\mathcal{S}^{th}_{18}$ type of radial form factor for the power:
+
+\begin{displaymath} \mathcal{S}^{th}_{18} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{flat radial form factor} \\
+ N_{\rm rad} & \textrm{number of point in the radial form factor table.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{19}$ number of points in the user-defined time-power table.
+
+\item $\mathcal{S}^{th}_{20}$ type of fluid:
+\begin{displaymath} \mathcal{S}^{th}_{20} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{light water (H$_2$O)} \\
+ 1 & \textrm{heavy water (D$_2$O).} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{21}$ flag indicating if the gap is considered:
+\begin{displaymath} \mathcal{S}^{th}_{21} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{gap is considered} \\
+ 1 & \textrm{is not.} \\
+\end{array} \right.
+\end{displaymath}
+
+\item $\mathcal{S}^{th}_{22}$ flag indicating the pressure drop option:
+\begin{displaymath} \mathcal{S}^{th}_{22} = \left\{
+\begin{array}{rl}
+ 0 & \textrm{no pressure drop} \\
+ 1 & \textrm{pressure drop is computed.} \\
+\end{array} \right.
+\end{displaymath}
+
+\end{itemize}
+
+The array $\mathcal{R}^{th}_{i}$ contains the following information: 
+
+\begin{itemize}
+\item $\mathcal{R}^{th}_{1}$ contains the current time step in s. 
+\item $\mathcal{R}^{th}_{2}$ contains the fraction of reactor power released in fuel.
+\item $\mathcal{R}^{th}_{3}$ contains the critical heat flux in W/m$^2$.
+\item $\mathcal{R}^{th}_{4}$ contains the inlet coolant velocity in m/s.
+\item $\mathcal{R}^{th}_{5}$ contains the outlet coolant pressure in Pa.
+\item $\mathcal{R}^{th}_{6}$ contains the inlet coolant temperature in K.
+\item $\mathcal{R}^{th}_{7}$ contains the fuel porosity.
+\item $\mathcal{R}^{th}_{8}$ contains the fuel pellet radius
+\item $\mathcal{R}^{th}_{9}$ contains the internal clad rod radius in m.
+\item $\mathcal{R}^{th}_{10}$ contains the external clad rod radius in m.
+\item $\mathcal{R}^{th}_{11}$ contains the guide tube radius in m.
+\item $\mathcal{R}^{th}_{12}$ contains the hexagonal side in m. Used only for cluster geometries.
+\item $\mathcal{R}^{th}_{13}$ contains the temperature maximum absolute error (in K) allowed in the solution of the conduction equations.
+\item $\mathcal{R}^{th}_{14}$ contains the maximum relative error allowed in the matrix resolution of the conservation equations of the coolant.
+\item $\mathcal{R}^{th}_{15}$ contains the relaxation parameter for the multiphysics parameters (temperature of fuel and coolant  and density of coolant).
+\item $\mathcal{R}^{th}_{16}$ contains the time in s.
+\item $\mathcal{R}^{th}_{17}$ contains the heat transfer coefficient of the gap (if $\mathcal{S}^{th}_{10}=1$).
+\item $\mathcal{R}^{th}_{18}$ contains the heat transfer coefficient between the clad and fluid (if $\mathcal{S}^{th}_{11}=1$).
+\item $\mathcal{R}^{th}_{19}$ contains the surface temperature weighting factor of effective fuel temperature for the Rowlands approximation.
+\item $\mathcal{R}^{th}_{20}$ reactor power, as defined after the {\tt POWER-LAW} keyword.
+\item $\mathcal{R}^{th}_{21}$ maximum of variable variations in local parameters (used for time step adjustment strategy).
+\item $\mathcal{R}^{th}_{22}$ contains the rugosity of the fuel rod in m, used in M\"uller-Steinhagen correlation for coolant friction.
+\item $\mathcal{R}^{th}_{23}$ contains the angle in radians of the fuel channel with respect of the vertical axis.
+\end{itemize}
+
+\subsubsection{The \moc{HISTORY-DATA} sub-directory}\label{sect:thmdirhistorydata}
+
+In the \moc{HISTORY-DATA} directory, the following sub-directories will be found:
+\begin{DescriptionEnregistrement}{Sub-directories in \moc{HISTORY-DATA} directory}{7.0cm} \label{tabl:tabhistorydatadir}
+ \DirEnr
+ {TIMESTEP0000}
+ {sub-directory containing all the values of the thermal-hydraulics parameters computed by the \moc{THM:} module {\sl in steady-state conditions}.}
+ \DirEnr
+ {TIMESTEP{\sl numt}}
+ {sub-directories containing all the values of the thermal-hydraulics parameters computed by the \moc{THM:} module in transient conditions at a given time index {\sl numt}. {\sl numt} can take values between 1 and 9999 in I4.4 format.}
+\end{DescriptionEnregistrement}
+
+\noindent In the \moc{TIMESTEP0000} and in each of the \moc{TIMESTEP}{\sl numt} sub-directories, the following records will be found:
+\begin{DescriptionEnregistrement}{Records in \moc{TIMESTEP} directories}{7.0cm} \label{tabl:tabtimestepdir}
+ \RealEnr
+ {TIME\blank{8}}{$1$}{$s$}
+ {time}
+ \DirlEnr
+ {\moc{CHANNEL}\blank{5}}{$N_{\rm ch}$}
+ {list of $N_{\rm ch}$ sub-directories containing all the values of the thermal-hydraulics parameters computed by the \moc{THM:} module and sorted channel by channel.}
+\end{DescriptionEnregistrement}
+
+\noindent In each of the \moc{CHANNEL} sub-directories, the following records will be found:
+\begin{DescriptionEnregistrement}{Records in each \moc{CHANNEL} directory}{7.0cm} \label{tabl:tabchanneldir}
+ \RealEnr
+ {VINLET\blank{6}}{$1$}{$m.s^{-1}$}
+ {inlet velocity}
+ \RealEnr
+ {TINLET\blank{6}}{$1$}{$K$}
+ {inlet temperature}
+ \RealEnr
+ {PINLET\blank{6}}{$1$}{$Pa$}
+ {inlet pressure}
+ \RealEnr
+ {VELOCITIES\blank{2}}{$N_{\rm z}$}{$m.s^{-1}$}
+ {velocity in each of the $N_{\rm z}$ bundles of the channel numbered {\sl numc}}
+ \RealEnr
+ {PRESSURE\blank{4}}{$N_{\rm z}$}{$Pa$}
+ {pressure in each bundle of the channel}
+ \RealEnr
+ {ENTHALPY\blank{4}}{$N_{\rm z}$}{$J.kg^{-1}$}
+ {enthalpy in each bundle of the channel}
+ \RealEnr
+ {DENSITY\blank{5}}{$N_{\rm z}$}{$kg.m^{-3}$}
+ {density in each bundle of the channel}
+ \RealEnr
+ {LIQUID-DENS\blank{1}}{$N_{\rm z}$}{$kg.m^{-3}$}
+ {density of liquid phase in each bundle of the channel}
+ \RealEnr
+ {TEMPERATURES}{$N_{\rm z}, N_{\rm dtot}$}{$K$}
+ {distribution of the temperature in the fuel-pin for each bundle of the channel}
+ \RealEnr
+ {CENTER-TEMPS}{$N_{\rm z}$}{$K$}
+ {center fuel pellet temperature in each bundle of the channel}
+ \RealEnr
+ {RADII}{$N_{\rm z}, N_{\rm dtot}-1$}{$m$}
+ {fuel and clad radii}
+\end{DescriptionEnregistrement}
+
+\clearpage
-- 
cgit v1.2.3

